Multicomponent precast concrete tanks would be useful in geographical areas where on site sewage treatment and disposal is required but standard 1200 gallon or larger precast concrete septic tanks cannot be installed because the heavy lifting and transporting equipment cannot access the disposal site. To date, in these areas, lightweight fiberglass tanks, or an equal, are installed because they can be lifted and installed by hand. Fiberglass tanks are subject to failure to a much higher degree than concrete tanks and therefore are less desirable. Furthermore, some jurisdiction will not allow the installation of fiberglass tanks.
Multicomponent precast concrete tanks can be designed and manufactured so that the components will be sufficiently light to allow the standard construction backhoe to pick up the components from the delivery vehicle, carry them to the disposal site, lower them into the hole and align them for cabling. A small mobile crane could also perform this job.
There are many situations where the replacement of an existing septic tank or the addition of another septic tank is necessary in an area of mature landscaping. The standard precast concrete septic tank that is delivered and placed by large, heavy duty lifting equipment would cause extensive damage to the landscaping beyond the scope of damage caused by the construction backhoe digging the holes. This is especially true if any turning or maneuvering is required. Most septic tank systems are designed to be installed behind the residence or building with the tank placed between 5 and 15 feet from the residence or building. The components could be brought to the site by the construction backhoe that dug the placement hole causing no more damage than is necessary by the smallest piece of equipment.
Multicomponent precast concrete tanks could be designed into any transportable component size that would allow movement over roads and highways. The size could meet the needs of any residential, commercial or public utility use that cast in place concrete tanks could not meet.
Multi-component tanks have been known in the prior art, but none of them have the advantages or features particular to the present invention. For example, U.S. Pat. No. 1,715,466 to Miller discloses a multiple unit septic tank that can be assembled to any desired length by selecting the number of units needed. The individual units are connected by aligning a flange, with a tapered opening, of one unit with a smaller, tapered flange of another unit. Each flange is provided with a groove such that the groove of one flange mates with the groove of the other flange. Grout or plaster is poured into this groove to secure the two units together in alignment and to seal the two together. This septic tank suffers the problems associated with the settling of the ground beneath the separate units. Each unit is only directly connected with an adjacent unit. Therefore, there is no structural integrity between two units that are separated by an intermediate unit. Furthermore, these units are placed into the ground vertically as opposed to being laid horizontally and connected serially with the circular openings of each unit cooperating with the circular openings of other units, which is a way that provides more strength.
Another sectional tank is shown by U.S. Pat. No. 1,422,674 to Cook. Cook discloses rectangular tanks that are connected side to side. These tanks also lack the structural integrity and the strength of the tanks of the present invention.